I don't know if you or maybe your HOA would be interested in getting a Jenson Lake Mower? (I used to manufacture it before selling to Elastec, Inc. in 2020.) It would allow you to cut exactly where you want and leave the rest.
From what our customers told us over the years, you want to be sure to mow before the plants form seeds; that way you should see "significant reduction in growth".
The person I'm quoting was managing two lakes. He mounted two Lake Mowers one on each side of his boat, so he could cut 8 feet wide.
